How to Convert Multiple HDRU Files to APNG?
1. Download and Install reaConverter
reaConverter is quick to download, install and launch. This standalone software is extremely efficient in managing a wide range of batch conversions. reaConverter is incredibly powerful and boasts an extensive variety of features.
2. Load your HDRU files
Start reaConverter and load all the .hdru files you intend to convert into .apng. The software supports multiple HDRU conversion and processes all files locally on your computer.
Select HDRUs from a folder or by drag-and-dropping them directly into the reaConverter window.

3. Select APNG as output format
Pick the APNG as output format and choose the destination folder where you want to save new .apng files.

4. Start HDRU to APNG conversion
Then simply press Convert button and your conversion will begin in no time!

Once the conversion is complete, you can find your APNG files in the destination folder you selected.